JPH07261010A - Replica diffraction grating - Google Patents

Abstract

PURPOSE:To obtain a replica diffraction grating with which stable spectrometry is executable by using a material having a low coefft. of expansion for the replica substrate of the replica diffraction grating formed by press-adhering a metallic thin film and the replica substrate via an adhesive, then peeling both and reversally adhering the metallic thin film to the replica substrate. CONSTITUTION:A thin oil film 3 is formed by using silicone grease as a release agent on a master diffraction grating and an aluminum thin film 4 is evaporated by vacuum deposition thereon. Next, the replica substrate 6 formed by using the material having a low coefft. of expansion is prepd. and its surface is washed with CFC(chlorofluorocarbon) 113, etc., and thereafter, the adhesive 5 is applied thereon. The replica substrate 6 and the master diffraction grating are then adhered. The aluminum thin film 4 transfer to the replica substrate 6 and the replica diffraction grating is produced when the replica substrate 6 is peeled with the release agent 3 as a boundary after curing of the adhesive. The material having a low coefft. of expansion is used for the replica substrate 6 in such a manner and, therefore, the replica diffraction grating having a stable dispersion angle to a temp. change is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a replica diffraction grating used for spectroscopy in ultrahigh vacuum.

[0002]

2. Description of the Related Art A method of mass-producing diffraction gratings (replica diffraction gratings) by making many replicas from a master diffraction grating has been conventionally performed, and a typical method thereof is as follows.

That is, first, a master diffraction grating is manufactured by depositing a metal thin film such as aluminum on a glass substrate and forming a grating groove in the film. Using this master as a mold, a thin oil film is formed on the lattice surface as a release agent, and an aluminum thin film is formed on it by vacuum deposition, and then a replica substrate is applied with an adhesive (heat resistant resin) on this aluminum thin film. After the adhesive is cured and the adhesive is cured, the replica substrate is peeled from the mother die, whereby the aluminum thin film moves to the replica substrate side, and a replica diffraction grating is obtained. The replica substrate used here is BK7, BS.
C2, Pyrex glass, soda glass, etc. are common.

[0004]

However, since the material used for the conventional replica substrate has a large expansion coefficient, the temperature of the diffraction grating may rise and the substrate may expand due to the incident light source or the incident light itself. there were. The expansion of the substrate brings about a change in grating groove spacing, which causes a change in chromatic dispersion. Therefore, depending on the situation, it is necessary to recalibrate the wavelength or to adjust the temperature of the spectroscope, and the apparatus itself becomes large-scale.

Further, a diffraction grating used for a high-power laser, a vacuum ultraviolet region, etc. needs to be resistant to temperature rise and less susceptible to radiation damage. Because of the change, it was not available in these areas.

Therefore, an object of the present invention is to provide a replica diffraction grating which does not have the above-mentioned problems and can perform stable spectroscopy.

[0007]

In order to solve the above problems, the present invention forms a metal thin film on the grating surface of a master diffraction grating, press-contacts the metal thin film and a replica substrate with an adhesive, and then peels them off. In a replica diffraction grating in which the metal thin film is reverse-bonded to a replica substrate, the replica substrate is made of a material having a low expansion coefficient.

Here, the master diffraction grating is glass,
An inorganic material such as SiO ₂ is directly engraved on the substrate, or a metal thin film such as aluminum is vapor-deposited on the substrate and engraved on it. The engraved area becomes the lattice plane. . The engraved line may be a machine engraved line by a diffraction grating engraving device or an engraved line by ion beam etching.

Examples of the metal thin film include thin films of aluminum, gold, platinum and the like, and these thin films are formed on the grating surface of the master diffraction grating by, for example, vacuum deposition. After forming the metal thin film, a release agent is applied to the grating surface of the master diffraction grating. As the release agent, for example, silicone grease or the like can be used.

As the material having a low coefficient of expansion used as the replica substrate, for example, quartz glass or zerodur (SCHO) is used.
Examples thereof include low expansion crystal glass such as TT Co., Ltd. and Cristlon (manufactured by HOYA Co., Ltd.).

As an adhesive for adhering the metal thin film and the replica substrate, a thermosetting resin such as urea resin, melamine resin, phenol resin, epoxy resin, or an ultraviolet curable resin can be used. A visible light curable resin may be used for the purpose of reducing the influence. In particular, the use of the visible light curable resin eliminates the risk of large-scale equipment required when using the ultraviolet curable resin and accidents (blindness, burns) during operation. Further, it is possible to bond thick glass on the order of cm, which was impossible with the ultraviolet curable resin. As the visible light curable resin, for example, B
ENEFIX VL (manufactured by Adel Co., Ltd.) can be mentioned, but the present invention is not limited thereto.

[0012]

According to the present invention, since the replica substrate is made of a material having a low expansion coefficient, a replica diffraction grating having a stable dispersion angle with respect to temperature changes can be obtained.

[0013]

【Example】

<Production of Replica Diffraction Grating> A process of producing the replica diffraction grating of the present invention will be described with reference to the drawings.

First, the flat glass substrate 1 (quartz glass: 6)
0mm x 60mm x 11.3mm) photoresist O
FPR5000 (manufactured by Tokyo Ohka Co., Ltd.) is coated to a thickness of 0.4 μm, and the holographic exposure method (laser wavelength 4
41.6 nm) to form lattice grooves (1200 / mm). Then, using the resist pattern as a mask, the cross-sectional shape of the groove with a blaze angle of 4 degrees is made into a sawtooth shape by ion beam etching, and an aluminum thin film (thickness 0.2 μm) 2 is vacuum-deposited on it, and the master diffraction Produce a lattice. This state is shown in FIG.

A thin oil film 3 (thickness: about 1 nm) is formed on the master diffraction grating using silicon grease as a mold release agent.
An aluminum thin film (having a thickness of 0.2 μm) 4 is vacuum-deposited thereon. This state is shown in FIG.

Next, a replica substrate (quartz glass; 60 mm)
X 60 mm x 11.3 mm) 6 is prepared, and the surface thereof is washed with Freon 113 (or either Freon (made by Mitsui DuPont Fluorochemical)) or the like, and then an adhesive (heat resistant epoxy resin) 5 is applied. . Then, the replica substrate 6 and the above-mentioned master diffraction grating are bonded. This state is shown in FIGS. 1 (c) and 1 (d).

After the adhesive is cured, the replica substrate 6 is peeled off with the release agent 3 as a boundary (FIG. 1 (e)), the aluminum thin film 4 is transferred to the replica substrate 6, and a replica diffraction grating having 1200 grooves / mm is produced. To be done. The state at this time is shown in Figure 1.
(F).

<Measurement of Change in Number of Grooves with Temperature> Table 1 shows the results of measuring the change in the number of grooves by heating the replica diffraction grating of the present invention and the replica diffraction grating whose substrate is soda glass with a halogen lamp. In addition, the measurement of the number of grooves is H
The e-Ne laser light was made incident vertically on the diffraction grating, the diffraction grating was rotated so that the first-order diffracted light returned to the laser, and the rotation angle was read by a rotary encoder. The temperature was measured by attaching a thermocouple to the portion of the diffraction grating where the laser light was applied.

[0019]

[Table 1] From this table, it can be seen that the replica diffraction grating of the present invention does not change the number of grooves even if the temperature changes.

[0020]

According to the present invention, since a replica diffraction grating having a stable dispersion angle with respect to temperature changes can be obtained, stable spectroscopy can be performed at any temperature, and a physical phenomenon that could not be measured until now was discovered. it can.

It can also be used for heat-intensive applications such as spectroscopy of a strong beam such as SR light, which can contribute to the development of science and technology.

[Brief description of drawings]

FIG. 1 is a process drawing of manufacturing a replica diffraction grating of the present invention.

[Explanation of symbols]

 1: Glass substrate 2: Aluminum thin film 3: Release agent 4: Aluminum thin film 5: Adhesive 6: Replica substrate 7: Silicon grease

Claims (2)

[Claims] 1. A replica obtained by forming a metal thin film on a grating surface of a master diffraction grating, press-contacting the metal thin film and a replica substrate with an adhesive, and then peeling the metal thin film and inverting and adhering the metal thin film to the replica substrate. In the diffraction grating, the replica diffraction grating, wherein the replica substrate is made of a material having a low expansion coefficient. 2. The replica diffraction grating according to claim 1, wherein
A replica diffraction grating using a visible light curable resin as an adhesive.